Photoelectric conversion device, image display, method of manufacturing photoelectric conversion device, and method of manufacturing image display

ABSTRACT

A photoelectric conversion device includes a plurality of photoelectric conversion regions disposed over a substrate, and a colored region disposed among the photoelectric conversion regions over the substrate, the colored region forming an image over the substrate.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a photoelectric conversion device thatis manufactured by using a liquid containing a silicon compound, animage display, a method of manufacturing a photoelectric conversiondevice, and a method of manufacturing an image display.

2. Related Art

Photoelectric conversion devices typified by solar cells have attractedincreasing attention as an environmentally friendly power supply.Single-crystal silicon solar cells, which are used for e.g. a powersupply for an artificial satellite, and solar cells employingpolycrystalline silicon or amorphous silicon have been widely used forindustrial use and home use.

Typically an amorphous silicon solar cell has a so-called PIN structurein which a light-absorbing layer composed of an intrinsic-type (I-type)semiconductor layer is interposed between a P-type semiconductor layerand an N-type semiconductor layer. The amorphous silicon solar cellutilizes a built-in electric field arising in the I-semiconductor layerto thereby extract the photocurrent and photovoltage from the electrode.

International Patent Publication WO00/59044, which is a first example ofthe related-art documents, has proposed a method for manufacturing asolar cell at low costs without using large-scale equipment. In themethod, a liquid coating composition containing a silicon compound isapplied over a substrate to form a coating film, and then the coatingfilm is converted into a silicon film by heat treatment and/or opticaltreatment. The silicon film is used as a semiconductor layer.

In step with widening of application range of solar cells, needs forcharacters and graphics to be represented as design on the solar cellpart have been increasing. For example, there are needs for a facephotograph, name and so on to be represented on an IC card of whichentire body is formed of a solar cell.

Some related-art documents disclose methods for representing charactersand graphics on a solar cell part. For example, JP-A-10-308525, which isa second example of the related-art documents, discloses a method inwhich solar cell panels are arranged so that a two-dimensionalrepresentation pattern is formed in a mosaic manner.

Furthermore, JP-A-8-88383, which is a third example of the related-artdocuments, discloses a method in which the contour shape of atransparent film on the surface of a solar cell is partially varied toform characters and picture patterns on the surface.

In addition, JP-A-2004-228450, which is a fourth example of therelated-art documents, discloses a method in which electrodes,semiconductor layers, and a colorant layer are formed into a shape ofgraphics and the like to be represented.

The methods of the second to fourth examples however cannot allowrepresentation of minute graphics and high-definition photographs.Moreover, it is difficult in terms of costs to apply these methods tofabrication of products such as ID cards, which are fabricated on ahigh-mix/low-volume production basis.

SUMMARY

An advantage of some aspects of the invention is to provide aphotoelectric conversion device provided with high-definition images,and a manufacturing method thereof.

A photoelectric conversion device according to a first aspect of theinvention includes a plurality of photoelectric conversion regionsdisposed over a substrate, and a colored region disposed among thephotoelectric conversion regions over the substrate. The colored regionforms an image over the substrate.

The first aspect allows the same surface to have both a representationfunction and a photoelectric conversion function, which can enhance theuse efficiency of the device surface.

It is preferable that the number of photoelectric conversion regions perunit area is substantially uniform across the entire substrate. Thisregion number uniformity allows the performance of the photoelectricconversion device to be uniform across the entire substrate.

In addition, it is preferable that the number of colored regions perunit area is also substantially uniform across the entire substrate.

Furthermore, it is preferable that the area ratio B/A between thephotoelectric conversion regions A and the colored regions B is equal toor larger than 1. Such an area ratio allows formation of high-definitionimages.

The images encompass e.g. characters, photographs, and symbol marks.

A photoelectric conversion device according to a second aspect of theinvention includes a first electrode formed on a substrate, afirst-conductivity-type semiconductor layer formed on the firstelectrode, a plurality of intrinsic-type (I-type) semiconductor filmsformed on the first-conductivity-type semiconductor layer, asecond-conductivity-type semiconductor layer formed on the plurality ofI-type semiconductor films, and a second electrode formed on thesecond-conductivity-type semiconductor layer. The plurality of I-typesemiconductor films are formed into an island shape with a gap beingensured among the I-type semiconductor films. A colorant is disposed ona region that does not overlap with the plurality of I-typesemiconductor films. An image that includes the colorant as a componentthereof is formed. The colorant may be formed on the second electrode.Alternatively, the colorant may be formed on a region that existsbetween the first-conductivity-type semiconductor layer and thesecond-conductivity-type semiconductor layer, and does not have theI-type semiconductor film thereon.

The second aspect allows the same surface to have both a representationfunction and a photoelectric conversion function, which can enhance theuse efficiency of the device surface.

Moreover, when an insulating film is formed on the regions that existbetween the first-conductivity-type semiconductor layer and thesecond-conductivity-type semiconductor layer, and do not have the I-typesemiconductor film thereon, short-circuit between thefirst-conductivity-type and second-conductivity-type semiconductorlayers via the region on which the I-type semiconductor film is notformed can be prevented. Instead of an insulating film, a semiconductorfilm having a thickness smaller than that of the I-type semiconductorfilm may be formed.

In addition, in the photoelectric conversion device according to thesecond aspect, a region, on the second-conductivity-type semiconductorlayer, that does not overlap with the colorant and the colorant arepreferably used as a component that forms the image.

Thus, such image processing is allowed that the region, on thesecond-conductivity-type semiconductor layer, that does not overlap withthe colorant is also used as another colorant. Therefore, the quality ofthe image can be enhanced.

An image display according to one embodiment of the invention includesthe above-described photoelectric conversion device.

Thus, high-definition images can be formed on the image display, andthus the functionalities and aesthetic properties of the image displaycan be enhanced. In addition, supply of drive power to an informationdisplay unit or the like incorporated in the image display is allowed.The term image display encompasses IC cards, photographs, posters,cellular phones and signboards that are provided with a photoelectricconversion device. In addition, the image display also encompassesoverall equipment having a decorative surface thereon, such asautomobiles and airplanes. Furthermore, the image display alsoencompasses real-estate properties, such as wall surfaces of buildings.

A method of manufacturing a photoelectric conversion device according toa third aspect of the invention includes forming afirst-conductivity-type semiconductor layer on a substrate, disposing aplurality of liquid materials on the first-conductivity-typesemiconductor layer so that a gap is ensured among the liquid materials,and baking the plurality of liquid materials to form a plurality ofintrinsic-type (I-type) semiconductor films. The method also includesforming a second-conductivity-type semiconductor layer on the pluralityof I-type semiconductor films, and disposing a colorant on a region thatdoes not overlap with the plurality of I-type semiconductor films. Thecolorant is a component that forms an image.

The third aspect allows the same surface to have both a representationfunction and a photoelectric conversion function, which can enhance theuse efficiency of the device surface.

The plurality of liquid materials and the colorant are preferablydischarged from a nozzle of an ink jet device. Thus, the I-typesemiconductor films and the colorant can be disposed on a desiredposition.

Furthermore, the method according to the third aspect may furtherinclude prior to the disposing a plurality of liquid materials,determining arrangement of the plurality of liquid materials and thecolorant based on image processing information.

The preliminary determination of components that form an image allowsthe plurality of liquid materials to be disposed on adequate placeswithout significantly lowering the image quality.

In addition, a method of manufacturing an image display according to oneembodiment of the invention employs the above-described method ofmanufacturing a photoelectric conversion device.

Thus, high-definition images can be formed on the image display, andthus the functionalities and aesthetic properties of the image displaycan be enhanced. In addition, supply of drive power to an informationdisplay unit or the like incorporated in the image display is allowed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers refer to like elements.

FIG. 1 is a perspective view illustrating a photoelectric conversiondevice according to one embodiment of the invention.

FIGS. 2A to 2G are explanatory diagrams illustrating manufacturing stepsfor a photoelectric conversion device according to one embodiment of theinvention.

FIG. 3 is a diagram illustrating a droplet discharge device used in amethod of manufacturing a photoelectric conversion device according toone embodiment of the invention.

FIGS. 4A and 4B are plan views of a photoelectric conversion deviceaccording to one embodiment of the invention.

FIGS. 5A to 5H are explanatory diagrams illustrating manufacturing stepsfor a photoelectric conversion device according to a second embodimentof the invention.

FIG. 6 is a diagram illustrating one example of a portable deviceaccording to one embodiment of the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention will be described below with reference tothe drawings.

First Embodiment

FIG. 1 is a perspective view illustrating a photoelectric conversiondevice 1 according to an embodiment of the invention. In the followingdescription, the upper and lower sides of the drawing plane of FIG. 1are defined as the upper and lower sides of the photoelectric conversiondevice 1, respectively. Therefore, the surfaces of each layer (eachmember) on the upper and lower sides of the drawing plane of FIG. 1 arereferred to as an upper surface and a lower surface, respectively.

The photoelectric conversion device 1 shown in FIG. 1 is a so-called dryphotoelectric conversion device, which requires no electrolyte solution.The photoelectric conversion device 1 includes a substrate 10, a firstelectrode (planar electrode) 12, a P-type semiconductor layer 14 as afirst-conductivity-type semiconductor layer, an I-type semiconductorlayer 16, an N-type semiconductor layer 18 as a second-conductivity-typesemiconductor layer, and a second electrode (counter electrode) 20. Onthe upper surface of the second electrode 20, a colorant layer 22 (thedotted area in FIG. 1) forms a graphic. Coupling the first electrode 12and the second electrode 20 via an external circuit 8 allows a current(photogenerated current) to flow through the external circuit 8. Thestructure of the layers (members) will be described below.

The substrate 10 supports thereover the first electrode 12, the P-typesemiconductor layer 14, the I-type semiconductor layer 16, the N-typesemiconductor layer 18, and the second electrode 20. The substrate 10 ismade of a flat plate (or layer) member.

As shown in FIG. 1, the photoelectric conversion device 1 receives lightsuch as sunlight (referred to simply as light, hereinafter) through thesubstrate 10 and the first electrode 12, so as to be put into use.Therefore, it is preferable that the substrate 10 and the firstelectrode 12 are substantially transparent (colorless transparent, colortransparent or semi-transparent). The substrate 10 with transparencyallows light to reach the I-type semiconductor layer 16 efficiently.

FIGS. 2A to 2G illustrate manufacturing steps for the photoelectricconversion device 1.

Step of Forming First Electrode

Referring initially to FIG. 2A, the first electrode 12 is formed on thesubstrate 10.

Examples of the material of the substrate 10 include various glassmaterials, various ceramic materials, and various resin materials suchas polycarbonate (PC) and polyethylene terephthalate (PET). Thesubstrate 10 may be formed of a single layer, or alternatively may beformed of a multi-layered body including plural layers.

The average thickness of the substrate 10 is not particularly limitedbut adequately set depending on its material, application and so on. Thefollowing thickness condition is available for example.

When the substrate 10 is composed of a hard material, the averagethickness thereof is preferably about 0.1-1.5 mm, and is more preferablyabout 0.8-1.2 mm. When the substrate 10 is a flexible substrate(flexible substrate composed mainly of a resin material), the averagethickness thereof is preferably about 0.5-150 μm, and is more preferablyabout 10-75 μm.

In the case of mounting the photoelectric conversion device 1 on any ofvarious electronic apparatuses, a constructional member of theelectronic apparatus can be used as the substrate 10 of thephotoelectric conversion device 1.

The upper surface of the substrate 10 has thereon the layer firstelectrode (planar electrode) 12. Any of the following materials can beused for the first electrode 12: various metal oxides (transparentconductive oxides) such as indium tin oxide (ITO), tin oxide doped withfluorine (FTO), indium oxide (IO), and tin dioxide (SnO₂); various metalmaterials such as aluminum, nickel, cobalt, platinum, silver, gold,copper, molybdenum, titanium, tantalum, and an alloy including any ofthese metals; various carbon materials such as carbon, carbon nanotubes,and fullerenes; and so on. Of these materials, one kind or a combinationof two or more kinds may be used. Use of sputtering, a spray method, anink jet method or another deposition method allows formation of athin-film electrode composed of any of these materials.

The average thickness of the first electrode 12 is not particularlylimited but adequately set depending on its material, application and soon. The following thickness condition is available for example. When thefirst electrode 12 is composed of any of various metal oxides, theaverage thickness thereof is preferably about 0.05-5 μm, and is morepreferably about 0.1-1.5 μm. When the first electrode 12 is composed ofany of various metal materials and carbon materials, the averagethickness thereof is preferably about 0.01-1 μm, and is more preferablyabout 0.03-0.1 μm.

Step of Forming P-type Semiconductor Layer

Referring next to FIG. 2B, formed on the first electrode 12 is theP-type semiconductor layer 14 as a first semiconductor layer.

The P-type semiconductor layer 14 can be formed by using a liquidmaterial prepared through the following procedure. Specifically, asilicon compound of a general formula Si_(a)X_(b)Y_(c) is mixed with asilicon compound (a silane compound in particular) having a ringsystemand expressed by a general formula Si_(n)X_(m). X denotes a hydrogenatom and/or a halogen atom. n denotes an integer larger than 4. mdenotes an integer represented by any of n, 2n−2 and 2n. Subsequently,the mixture is irradiated with ultraviolet rays so as to be polymerized,and then is diluted with a solvent such as toluene, followed by beingpercolated through a filter. This solution is used as the liquidmaterial. There is no particular limitation on the solvent as long as itdissolves the above-described silane compound and/or modified silanecompound, and does not react with the solute. As a modified silane usedfor forming the P-type semiconductor layer, a silane compound includinga boron atom is available for example.

The above-described liquid material can be applied on the firstelectrode 12 by using spin coating, roll coating, curtain coating, dipcoating, a spray method, an ink jet method, or another coating method.The coating thickness is about several tens nanometers for example.After the coating, the coated material is baked at 400° C. for 1 hourfor example, to thereby form doped amorphous silicon. The amorphoussilicon may be crystallized by laser irradiation or the like accordingto need.

A specific example of a method of forming a P-type amorphous siliconfilm is as follows. Specifically, 1 mg of 1-borahexaprismane(Compound 1) as a boron modified silane compound and 1 g ofcyclohexasilane are dissolved in 20 g of toluene to prepare a coatingsolution. The solution is spin-coated on the substrate 10 in an argonatmosphere. The coated solution is dried at 150° C., followed by beingpyrolized at 450° C. in argon containing 3% of hydrogen, to thereby forma P-type amorphous silicon film having a thickness of about 60 nm.

Step of Forming Precursor Film of Silicon Film

Referring next to FIG. 2C, a liquid silicon material containing noimpurity is discharged by an ink jet method so that droplets aredisposed on the P-type semiconductor layer 14. The discharged dropletsare dried to form precursor films 16′ of a silicon film.

As the liquid silicon material, a material prepared through thefollowing procedure can be used. Specifically, a silicon compound (asilane compound in particular) having a ringsystem and expressed by ageneral formula Si_(n)X_(m) (X denotes a hydrogen atom and/or a halogenatom, n denotes an integer larger than 4, and m denotes an integerrepresented by any of n, 2n−2 and 2n) is irradiated with ultravioletrays so as to be polymerized, and then is diluted with a toluene solventto about 10%, followed by being percolated through a filter.

FIG. 3 illustrates one example of a droplet discharge device (ink jetdevice) that is used for an ink jet method.

Referring to FIG. 3, a droplet discharge device 30 includes a table 32on which the substrate 10 is placed, and an X-axis drive roller 34 formoving the table 32 in the X-axis direction (main scanning). The device30 also includes a droplet discharge head 38 having nozzles 36, and aY-axis drive mechanism 40 for moving the droplet discharge head 38 inthe Y-axis direction (sub scanning).

A liquid silicon material is loaded in the droplet discharge head 38,and is discharged as droplets 42 from small orifices formed at end tipsof the nozzles 36.

The discharging of the droplets 42 from the small orifices of thenozzles 36 is associated with movement of the table 32 in the X-axisdirection and reciprocation of the droplet discharge head 38 in theY-axis direction. Thus, the above-described film is formed.

The droplets 42 can be disposed over the substrate 10 based oncalculation by the droplet discharge device based on information forprocessing a certain image. The certain image is an image (graphic)formed through a step of forming a colorant layer, to be describedlater.

Heat Treatment Step

Referring back to FIG. 2D, baking is carried out at 400° C. for 1 hour,and thus the precursor films 16′ of a silicon film are converted intoamorphous silicon films (I-type semiconductor layers) 16.

The film thickness decreases through the baking. In the method accordingto the embodiment, the droplets are formed to have a thickness of atleast 1 μm, preferably at least 2 μm, and more preferably at least 3 μm.

In the heat treatment, typically an arrival temperature lower than about550° C. offers an amorphous silicon film while a temperature above about550° C. offers a polycrystalline silicon film. In order to obtain anamorphous silicon film, a temperature in the range of 300-550° C. ispreferably used, and a temperature in the range of 350-500° C. is morepreferably used. An arrival temperature lower than 300° C. cannotadvance the pyrolysis of a silane compound sufficiently, and thereforefails to form a silicon film with sufficiently favorable characteristicsin some cases. It is preferable that the atmosphere for the heattreatment is an inactive gas such as nitrogen, helium or argon, or amixture of an inactive gas with a reducing gas such as hydrogen. Ifformation of a polycrystalline silicon film is intended, the obtainedamorphous silicon film may be irradiated with a laser, to thereby beconverted into a polycrystalline silicon film. It is preferable that theatmosphere for the laser irradiation is an inactive gas such asnitrogen, helium or argon, or a mixture of any of these inactive gaseswith a reducing gas such as hydrogen. That is, an atmosphere includingno oxygen is preferable. Note that if laser irradiation employing anexcimer laser or the like is implemented for discharged droplets insteadof the heat treatment therefor, a polycrystalline silicon film can beachieved directly. It is obvious that the crystallization by laserirradiation may be carried out after the formation of an amorphoussilicon film by baking.

Step of Forming Insulating Film

Referring next to FIG. 2E, gaps among the I-type semiconductor layers 16deposited in an island shape are filled with an insulating film 17. Thekind of the insulating film 17 is not particularly limited. For example,an SiO₂ film is available. Typical sputtering, CVD or another method canbe used for the formation thereof In the method of manufacturing aphotoelectric conversion device according to the embodiment, the I-typesemiconductor layers are formed by using a liquid material withoutrequiring vacuum processes. Therefore, if a method of using a liquidmaterial is employed in common to all other thin films, all the stepscan be implemented in the same equipment and under the same environment.For example, the insulating film 17 can be formed by applyingpolysilazane only on regions among the islands by an ink jet method, andthen the applied polysilazane is baked in an air atmosphere to therebyform an SiO₂ film. Alternatively, a liquid containing theabove-described silicon compound may be applied, and then the appliedliquid may be baked in an air atmosphere. It is preferable that thethickness of the insulating film 17 is in the range of about 200-500 nm.

The insulating film 17 can prevent the P-type semiconductor layer 14from being brought into contact with an N-type semiconductor layer to beformed later.

Also when a semiconductor film having a thickness smaller than that ofthe I-type semiconductor layers 16 is formed in the gaps among theI-type semiconductor layers 16 instead of the insulating film 17,similar advantages can be achieved. The semiconductor film can be formedby a method similar to that for the I-type semiconductor layers 16,described referring to FIGS. 2C and 2D.

Step of Forming N-type Semiconductor Layer and Second Electrode

Referring next to FIG. 2F, the N-type semiconductor layer 18 and thesecond electrode 20 are formed.

The N-type semiconductor layer 18 can be formed by using, in theabove-described method for forming the P-type semiconductor layer 14, aphosphorous modified silane compound instead of a boron modified silane.

Specifically, 1 mg of 1-phosphocyclopentasilane as a phosphorousmodified silane compound and 1 g of octasilacubane (Compound 2) aredissolved in a mixture solvent of 10 g of toluene andtetrahydronaphthalene to prepare a coating solution. The solution isspin-coated in an argon atmosphere. Subsequently, the coated solution isdried at 150° C., followed by being pyrolized at 450° C. in argoncontaining 3% of hydrogen, and thus the N-type semiconductor layer 18having a thickness of about 60 nm can be formed.

After the formation of the N-type semiconductor layer 18, an organiccompound liquid material containing indium and tin is applied, and thenheat treatment is carried out to convert the applied material into anITO film. The ITO film is used as the second electrode 20.

Step of Forming Colorant Layer

Referring next to FIG. 2G, the colorant layer 22 is formed on the secondelectrode 20 so that the colorant layer 22 represents a certain graphicshape. In order to form the colorant layer 22, a colorant is dischargedby an ink jet method with using the droplet discharge device shown inFIG. 3, to thereby dispose colorant droplets. Here, the colorant isdisposed so that the E-shape in FIG. 1 is formed.

FIG. 4A is a plan view illustrating part of the photoelectric conversiondevice 1 in which the colorant layer 22 has been formed. As shown in thedrawing, it is preferable that the colorant is disposed on the regionsthat do not overlap with the I-type semiconductor layers 16.

The colorant can be discharged from the droplet discharge device afterthe arrangement of the I-type semiconductor layers 16 and the colorantlayer 22 is calculated so that the I-type semiconductor layers 16 andthe colorant layer 22 form a certain image based on information forprocessing the certain image.

As shown in FIG. 4B, the colorant layer 22 may be disposed on theinsulating film 17, i.e. on the regions that exist between the P-typesemiconductor layer 14 and the N-type semiconductor layer 18, and do notoverlap with the I-type semiconductor layers 16.

In the examples of FIGS. 4A and 4B, only the colorant layer 22 forms animage. Alternatively, not only the colorant layer 22 but also part, ofthe N-type semiconductor layer 18, that does not overlap with thecolorant layer 22 may be used as a component of an image. By using partother than the colorant layer 22 as a component of an image, the qualityof the image can further be enhanced.

As the colorant of the colorant layer 22, any of various pigments andvarious dyes can be formed alone or in combination. Pigments aresuperior in that they exhibit less aging degradation. Dyes are superiorin that they have a higher adhesion to the second electrode 20.

As pigments, any of various organic pigments and various inorganicpigments can be used. Examples of the organic pigments includephthalocyanine pigments, azo pigments, anthraquinone pigments,azomethine pigments, quinophthalone pigments, isoindolinone pigments,nitroso pigments, perinone pigments, quinacridone pigments, perylenepigments, pyrrolopyrrole pigments, dioxazine pigments, and otherpigments. Examples of the inorganic pigments include carbon pigments,chromate pigments, sulfide pigments, oxide pigments, hydroxide pigments,ferrocyanide pigments, silicate pigments, phosphate pigments, and othersubstances such as cadmium sulfide and cadmium selenide.

Furthermore, examples of dyes include metal complex dyes such asRuL₂(SCN)₂, RuL₂Cl₂, RuL₂(CN)₂, Ruthenium 535-bisTBA (produced bySolaronix Co.), and [RuL₂(NCS)₂]₂H₂O, cyan dyes, xanthene dyes, azodyes, hibiscus dyes, blackberry dyes, raspberry dyes, pomegranate dyes,and chlorophyll dyes. Note that L in the above composition formulasrepresents 2,2′-bipyridine or a derivative thereof

Second Embodiment

In a second embodiment of the invention, after the N-type semiconductorlayer 18 is formed, the colorant layer 22 is formed on the N-typesemiconductor layer 18. FIGS. 5A to 5H illustrate manufacturing stepsfor a photoelectric conversion device 1 according to the secondembodiment of the invention. The steps shown in FIGS. 5A to 5E are thesame as those in the first embodiment.

Step of Forming N-type Semiconductor Layer

Referring to FIG. 5F, the N-type semiconductor layer 18 is formed.Similarly to the first embodiment, initially 1 mg of1-phosphocyclopentasilane as a phosphorous modified silane compound and1 g of octasilacubane (Compound 2) are dissolved in a mixture solvent of10 g of toluene and tetrahydronaphthalene to prepare a coating solution.The solution is spin-coated in an argon atmosphere. Subsequently, thecoated solution is dried at 150° C., followed by being pyrolized at 450°C. in argon containing 3% of hydrogen, and thus the N-type semiconductorlayer 18 having a thickness of about 60 nm can be formed.

Step of Forming Colorant Layer

Referring next to FIG. 5G, the colorant layer 22 is formed on the N-typesemiconductor layer 18 so that the colorant layer 22 represents acertain graphic shape. The colorant layer 22 is formed by discharging acolorant by an ink jet method similarly to the first embodiment.

Step of Forming Second Electrode

Referring next to FIG. 5H, an organic compound liquid materialcontaining indium and tin is applied on the colorant layer 22, and thenheat treatment is carried out to convert the applied material into anITO film. The ITO film is used as the second electrode 20.

Image Display

An image display according to one embodiment of the invention includesany of the above-described photoelectric conversion devices 1.

FIG. 6 is a plan view illustrating an IC card 100 to which an imagedisplay according to one embodiment of the invention is applied.

The IC card 100 is formed of a body 101 having a solar cell function,and includes on the body 101, an IC chip 102 storing information ofelectronic money and so on, and a display 103. A photograph 104, a logomark 105, and characters 106 printed on the body 101 are formed on thesolar cell by the method according to any of the embodiments of theinvention.

As an image display according to one embodiment of the invention,besides the IC card shown in FIG. 6, e.g. photographs, signboards and soon having a solar cell function are available. In addition, buttons andkeys included in an electronic apparatus such as a cellular phone andhaving a solar cell function are also available. Furthermore, the imagedisplays according to the embodiment encompass overall equipment havinga decorative surface thereon, such as automobiles and airplanes. Theimage displays also encompass real-estate properties, such as wallsurfaces of buildings.

1. A photoelectric conversion device comprising: a plurality ofphotoelectric conversion regions disposed over a substrate; and acolored region disposed among the photoelectric conversion regions overthe substrate, the colored region forming an image over the substrate.2. A photoelectric conversion device comprising: a first electrodeformed on a substrate; a first-conductivity-type semiconductor layerformed on the first electrode; a plurality of intrinsic-type (I-type)semiconductor films formed on the first-conductivity-type semiconductorlayer; a second-conductivity-type semiconductor layer formed on theplurality of I-type semiconductor films; and a second electrode formedon the second-conductivity-type semiconductor layer, wherein: theplurality of I-type semiconductor films are formed into an island shapewith a gap being ensured among the I-type semiconductor films; acolorant is disposed on a region that does not overlap with theplurality of I-type semiconductor films; and an image that includes thecolorant as a component thereof is formed.
 3. The photoelectricconversion device according to claim 2, wherein the colorant is formedon the second electrode.
 4. The photoelectric conversion deviceaccording to claim 2, wherein the colorant is formed on a region thatexists between the first-conductivity-type semiconductor layer and thesecond-conductivity-type semiconductor layer, and does not have theI-type semiconductor film thereon.
 5. The photoelectric conversiondevice according to claim 2, wherein an insulating film is formed on aregion that exists between the first-conductivity-type semiconductorlayer and the second-conductivity-type semiconductor layer, and does nothave the I-type semiconductor film thereon.
 6. The photoelectricconversion device according to claim 2, wherein a semiconductor filmhaving a thickness smaller than the thickness of the I-typesemiconductor film is formed on a region that exists between thefirst-conductivity-type semiconductor layer and thesecond-conductivity-type semiconductor layer, and does not have theI-type semiconductor film thereon.
 7. The photoelectric conversiondevice according to claim 2, wherein a region on thesecond-conductivity-type semiconductor layer and the colorant are usedas a component that forms the image, the region not overlapping with thecolorant.
 8. An image display comprising the photoelectric conversiondevice according to claim
 1. 9. A method of manufacturing aphotoelectric conversion device comprising: forming afirst-conductivity-type semiconductor layer on a substrate; disposing aplurality of liquid materials on the first-conductivity-typesemiconductor layer so that a gap is ensured among the liquid materials;baking the plurality of liquid materials to form a plurality ofintrinsic-type (I-type) semiconductor films; forming asecond-conductivity-type semiconductor layer on the plurality of I-typesemiconductor films; and disposing a colorant on a region that does notoverlap with the plurality of I-type semiconductor films, the colorantbeing a component that forms an image.
 10. The method of manufacturing aphotoelectric conversion device according to claim 9, wherein theplurality of liquid materials and the colorant are discharged from anozzle of an ink jet device so as to be disposed.
 11. The method ofmanufacturing a photoelectric conversion device according to claim 10,further comprising prior to the disposing a plurality of liquidmaterials: determining arrangement of the plurality of liquid materialsand the colorant based on image processing information.
 12. A method ofmanufacturing an image display, the method comprising the method ofmanufacturing a photoelectric conversion device according to claim 9.